尼莫地平对豚鼠耳蜗外毛细胞钙电流的影响

Effects of nimodipine on calcium currents in isolated outer hair cells of guinea pig cochlea

为研究尼莫地平对豚鼠耳蜗外毛细胞钙电流的影响，应用全细胞式记录膜片钳技术，观察１８只豚鼠耳蜗分离出的２０个外毛细胞中，用全细胞方式记录到通道电流２０次。结果发现，尼莫地平可部分阻断豚鼠耳蜗外毛细胞电压依赖性钙电流，减轻毛细胞内Ｃａ２＋负荷，其阻断作用是可逆的，对电流的抑制率与尼莫地平的浓度有关，其半数抑制浓度为６０．１４ｎｍｏｌ／Ｌ，对电流的最大抑制率为３４．１６％。推测尼莫地平在治疗梅尼埃病等内耳疾病方面有应用前景。

The effects of nimodipine on calcium currents in outer hair cells isolated from guinea pig cochlea were investigated using a wholecell recording patchclamp technique. External application of nimodipine (10 μmol / L) caused a decrease of voltagedependent calcium currents and an elevation of currentvoltage curve. The halfmaximal inhibition concentration of nimodipine inhibiting the voltagedependent calcium currents was 60.14 nmol/L, and the maximal inhibition was 34.16% .The present results demonstrate that nimodipine reversiblly and partially blocks the voltagedependent calcium currents in isolated outer hair cells of guinea pig cochlea in a concentrationdependent manner. It is suggested that nimodipine may be used in the treatment of Meniere disease through decreasing the influx of Ca2+ into the outer hair cells. 